Matthew,

Other than gambling, do you have any specific examples of how this could be
useful?

On Fri, May 20, 2016, 20:34 Johnson Lau via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> Using the hash of multiple blocks does not make it any safer. The miner of
> the last block always determines the results, by knowing the hashes of all
> previous blocks.
>
>
> == Security
>
> Pay-to-script-hash can be used to protect the details of contracts that
> use OP_PRANDOM from the prying eyes of miners. However, since there is also
> a non-zero risk that a participant in a contract may attempt to bribe a
> miner the inclusion of multiple block hashes as a source of randomness is a
> must. Every miner would effectively need to be bribed to ensure control
> over the results of the random numbers, which is already very unlikely. The
> risk approaches zero as N goes up.
>
>
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